As opposed to open surgery in which a surgeon cuts a relatively large incision in the skin of a patient for accessing internal organs, minimally invasive surgical procedures are performed by making relatively small incisions and then inserting tools through the incisions to access the organs. Minimally invasive surgery usually results in shorter hospitalization times, reduced therapy requirements, less pain, less scarring, and fewer complications.
Although minimally invasive surgical procedures involving small incisions include many advantages over open surgery, minimally invasive surgery can still create challenges to a surgeon. For example, the surgeon must typically rely on a miniature camera introduced through an incision to view the patient's internal organs and see how the movement and operation of the tools affects the organs. The camera transmits images to a visual display, allowing the surgeon to see the internal organs and tissues and to see the effect of other minimally invasive tools on the organs and tissues. In this way, the surgeon is able to perform laparoscopic surgery, dissection, cauterization, endoscopy, telesurgery, and the like.
Compared to open surgery, however, minimally invasive surgery presents limitations in visual and haptic perceptions, and creates challenges unique to this type of surgery. One of the major concerns relevant to both open surgery and minimally invasive surgery is the potential for tissue damage, possibly caused by inappropriate use of force or excessive application of energy/heat. For example, electrosurgical tools operate by stimulating tissue with a high frequency electric current. The frequency of the current controls the action of the tool, which can include sealing/coagulating and/or dissecting. In both open surgery and minimally invasive surgery, the tissue being sealed is clamped within the jaws of a tissue sealing tool and is not visible to the user, and therefore direct visualization is not helpful in determining when an electrosurgical endpoint has been reached, i.e., when the clamped tissue is completely sealed. Surgeons must often rely on experience and indirect visualization to determine when the tissue is sealed, dissected or when other changes have occurred in the tissue. Based on the foregoing, there is a need for improved minimally invasive surgical tools and in particular, there is a need for minimally invasive surgical tools having improved feedback related to the surgical procedure.